Separator sterilizable by superheated steam

ABSTRACT

A centrifugal separator comprising a drum whose driving spindle is rotatably mounted in a frame, a casing surrounding the drum and attached to the frame, is provided with a sealing means between the frame or casing and the drum to prevent passage of steam used for sterilizing, from the casing to within the frame. The sealing means can be in sliding sealing engagement with the frame and can be moved axially upwardly so that the upper end thereof is placed in sealing engagement with a sealing ring on the drum.

United States Patent 233/1 A 233/1 A 233/1 A [72] lnventor Heinrich Hemlort 5 R f r Cited 1 A I N figs- UNITED STATES PATENTS [2 1 P 2,992,843 7/1961 Smith [22] Filed Feb. 3, 1970 3,126,338 3/1964 Steinackerm. [45] Patented Aug. 10.1971 3 269 647 8/1966 sh [73] Assign Semi AG apiro Westphalia, Germany Primary Examiner-Jordan Franklin [32] Priority Feb. 28, 1969 Assistant Examiner-George l-l. Krizmanich [33] Germany Anomey- Burgess, Dinklage and Sprung 1311 P19102115 7 ABSTRACT: A centrifugal separator comprising a drum whose driving spindle is rotatably mounted in a frame, a casing [541 gggm STERIUZABLE BY SUPERHEATED surrounding the drum and attached to the frame, is provided 5 cm 40 F with a sealing means between the frame or casing and the drum to prevent passage of steam used for sterilizing, from the [52] 11.8. CI. 233/] A casing to within the frame. The sealing means can be in sliding [51] Int. Cl. 801d 21/26 sealing engagement with the frame and can be moved axially [50] Field of Search 233/1, 1 A, upwardly so that the upper end thereof is placed in sealing en- 20, 20 A gagement with a sealing ring on the drum.

0 2 r V A we a s a q a co co 1a 8 36 a? l6 at 1 a3 20 25 1:" {a J i m I; H e 1/ a Q (a 4 5 a SEPARATOR STERILIZABLE BY SUPERHEATED STEAM The invention relates to separators whose drum is enveloped by a stationary casing designed to catch and remove one or more of the components of the material being centrifuged. In the case of recovering a plurality of components the casing is divided into an appropriate number of stacked catching chambers, each of which is provided with an outlet. The casing can be composed of a number of parts. It is removably attached to the frame, which is also stationary. In addition to this catcher casing and its outlets, the separator can also be equipped with other material removing means, such as skimmer disks.

So that the bottom of the catcher casing will not rub against the rotating drum or spindle during operation, the stationary and the rotating parts are disposed at a distance from one another that is large enough to prevent interference even when the drum is unbalanced. Through this annular gap the inner part of the casing surrounding the drum communicates (through an additional intermediate chamber in some cases) with the inside of the lower part of the frame in which the transmission and the oil bath are housed.

German Pat. No. 487,302 discloses a labyrinth packing which, to a great extent, prevents the penetration of liquid and vapors into the liwer part of the frame. Nevertheless, a perfect seal cannot be obtained in this manner.

Separators of the above-described kind are used also in pharmaceutical industries for harvesting from nutrient solutions bacteria that are not too hazardous and are not sensitive to external influences. In order to protect the personnel from the bacteria, on the one hand, and on the other hand to protect the bacteria from undesired influences, a sterilization is undertaken, before ".ie centrifuging operation is begun and/or after it has ended, by feeding hot water or a suitable disinfectant solution to the rotating drum for a period of time. In the case ofdrumsoftheself-cleaning type, a so-called flush desludging is performed, so that the disinfectant solution can exercise its germicidal action also on the sludge catcher and on the outlets provided for the solids.

in the case of more hazardous bacteria and/or bacteria that are harder to kill and are more sensitive to external influences, this method of sterilization is not sufficient. In such cases, the use of superheated steam may be necessary, and it would have to be applied to all parts that come directly in contact with the material being separated or with its components. These parts include the drum, the sludge catcher or casing and its outlets, and other discharge devices and their fittings.

Steam sterilization could be performed with the drum standing still by introducing the superheated steam through the tube through which the liquid to be separated is delivered into the drum, so that it will pass from the drum into the outlet systems and through the open outlets of the drum into the catcher or casing. In the designs that have been known hitherto, however, it would also pass through the above-described annular gap between the floor of the casing and the rotating portion and through any labyrinth packings that might be present, into the lower part of the frame. The condensation that would there take place would, in the course of time, do damage to the drive system. For this reason, steam sterilization has not been employed in the centrifugal separators of the prior art.

The invention is directed to the problem of creating a design that makes it possible to hermetically seal the casing from the inside of the frame, thereby permitting the separator to be sterilized with steam, commonly superheated steam, and, therefore, to be used for the harvesting of hazardous and/or delicate bacteria.

The separator, according to the invention, is characterized by an axially displaceable closure body or sealing means which is in sliding seal engagement with the frame or the bottom of the catcher casing, and which in its uppermost position cooperates with a sealing ring disposed in the hub of the drum, a closable condensate drain communicating with the bottom of the catcher casing is also provided, for draining condensate from the casing.

In separators having a which drum, the device which feeds the control liquid and which is in the form of an annular hol low body, can serve as the closing body. In this case, the control fluid feed tube affixed to the hollow body must have the necessary flexibility, which can be achieved merely by bending it accordingly.

The axial displacement of the closing body can be performed, for example, by the turning, with a hand wrench, a plurality of shafts to whose extremities pins are eccentrically attached, which engage in recesses in the closure body.

The lower portion of the frame is kept germ-free during operation by known measures which do not pertain to the present invention.

The invention is represented by way of examples in the drawings, which relate to different types of drum construction:

FIG. 1 is a self-cleaning separator constructed according to the invention;

FIG. 2 is an enlarged view of a portion of the apparatus similar to that shown in FIG. 1;

FIG. 3 is a partial showing of a separator having a solid-wall drum, employing the construction according to the invention; and 1 FIG. 4 is an enlarged view indicating a preferred construction.

The invention is concerned with a separator comprising a drum the spindle of which is rotatably mounted in a stationary frame by means of bearings, and having a stationary casing mounted on the frame and disposed about the drum for receiving material discharged from the drum. Upon sterilizing the drum and the casing with steam, there is access for steam by the above-mentioned gap from the casing to the interior of the frame. The invention provides a sealing means between the frame or casing and the drum for eliminating said access when sterilizing the drum and the casing. The sealing means comprises an annular closure body, axially slidable in the frame or in the bottom of the casing. The closure body includes a first sleeve, disposed at one end thereof and which is in sliding seal engagement with the frame or casing, and a second sleeve disposed at the other end thereof. A sealing ring is mounted in the hub of the drum, axially aligned with the second sleeve of the closure body and is normally axially spaced therefrom. Means are provided for axially moving the sleeve to press the closure body against the sealing ring to provide said seal between the frame and drum for eliminating said access.

Referring to the drawings, the drum is indentified as l and the casing surrounding it is marked 2, the bottom 3 of the casing being attached to the frame 4. In the chamber 5 of frame 4 is housed the worm gear 6 and the rest of the drive which powers the spindle 7 and is immersed in an oil bath.

The drum is of the type which periodically ejects through orifices 8 in the drum periphery 9 the solids centrifuged from the liquid being treated. These solids are caught by the catcher I0 of casing 2 and carried out through the discharge I I.

The clarified fluid is delivered by a skimmer disk 12 into the discharge line 13 which is provided with a throttling member 14 and a pressure gauge 15.

The catcher chamber 10 communicates through the annular gap 16 with an intermediate chamber 17 which in turn communicates through an annular gap 18 and the neck bearing l9 with the chamber 5 in frame 4. The neck bearing 19 can be of the construction disclosed in German Pat. No. 1,031,222.

The control fluid for the operation of the member that opens and closes the ejection orifices 8 is brought in through a line 20 which empties into a bell-shaped hollow body or is carried along a hood 21.

According to the invention, this hood 21 serves as the closure body and comprises a first sleeve or cylinder 22 (FIG. 2) which is axially displaceable and is sealingly guided in the bottom 3 of the casing 2. The sleeve 22 is provided with recesses into which pins 23 engage which are mounted eccentrically on the end faces of rotatably mounted shafts 24. By turning the shafts 24, e.g., by means of a square drive 25 with, for example, a hand wrench, the closing body 21 can be displaced axially upward. in the upper position, a second sleeve 22a comes to rest against a sealing ring 27 disposed in the drum hub 26, thereby closing the annular gap 18. The casing 2 is provided with a bottom condensate drain 28 and the solids discharge 11 is provided with a shut-off means which is not shown.

With the drum stopped, when the sealing means 21 is pressed against the sealing ring 27 and superheated steam is introduced into the drum through the input tube 29 (FIG. ll), no steam can get into the bearings or chamber 5.

HO. 3 shows the apparatus according to the invention in conjunction with a solid-wall drum in which solids separated from the liquid being treated gather and which has to be opened in order to clean it out.

The seals illustrated include a sealing gasket 30 as can be seen in FIG. 4. The gasket can be mounted on either the sealing ring 27 or the second sleeve 22a of the closing body 21. Preferably it is mounted on the second sleeve 22a, as is shown in FIG. 4, as the gasket is then mounted in a stationary ele ment, rather than on a rotating member.

The apparatus according to the invention is also applicable to all other types of separating drums.

What I claim is 1. In a separator comprising a drum having a hub and as stationary parts a frame and casing, said casing being disposed about the drum for receiving material discharged from the drum, a rotatable driving spindle, a driving gear for driving the spindle, the drum being mounted on the spindle via the drum hub for rotation therewith, and a bearing disposed on the frame operatively interposed between the frame and the drum, wherein the interior of the casing surrounding the drum is normally in communication for fluid flow with the interior of the frame so that upon sterilizing with steam, there is access for steam to the bearing, the improvement of sealing means between the frame and the drum for eliminating said access when sterilizing, comprising: i

a. a closure body disposed about the spindle and axially slidable therealong, terminating at one end thereof in a first sleeve which is in sliding seal engagement with one of said stationary parts, and terminating at the other end thereof in a second sleeve,

b. a sealing ring mounted in the hub of the drum axially aligned with said second sleeve and normally axially spaced therefrom, and

c. means for axially moving the closure body to press said second sleeve into sealing engagement with the sealing ring to provide said seal between the frame and drum for eliminating said access.

2. Separator according to claim 1, and a condensate drain outfitted with a valve communicating with the casing for draining condensate from the casing with the closure body sealing the frame and drum.

3. Separator according to claim 1, said means for axially moving the closure body comprising rotatable shafts each having integral with one end thereof an eccentrically mounted pin, recesses in said closure body receiving said pins.

41. Separator according to claim 1, and a sealing gasket interposed between the sealing ring and said second sleeve mounted on the sealing ring or the second sleeve.

5. Separator according to claim 4, the gasket being mounted on the second sleeve.

Z gz g? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3.598.304 Dated Aug. 10, 1971 Inventor(s) Heinrich Hemfort It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Col. 1, line 37, change "ofdrum softheself" to of drums of the'self- -a Col. 2, line 3, change "which" to --selfcleaning--.

Signed and sealed this lhth day of March 1972.

(SEAL) Attest:

EDWARD M.FLETC IHER,JR. ROBERT GOTTSCHALK Attestlng Officer- Commissioner of Patents 

1. In a separator comprising a drum having a hub and as stationary parts a frame and casing, said casing being disposed about the drum for receiving material discharged from the drum, a rotatable driving spindle, a driving gear for driving the spindle, the drum being mounted on the spindle via the drum hub for rotation therewith, and a bearing disposed on the frame operatively interposed between the frame and the drum, wherein the interior of the casing surrounding the drum is normally in communication for fluid flow with the interior of the frame so that upon sterilizing with steam, there is access for steam to the bearing, the improvement of sealing means between the frame and the drum for eliminating said access when sterilizing, comprising: a. a closure body disposed about the spindle and axially slidable therealong, terminating at one end thereof in a first sleeve which is in sliding seal engagement with one of said stationary parts, and terminating at the other end thereof in a second sleeve, b. a sealing ring mounted in the hub of the drum axially aligned with said second sleeve and normally axially spaced therefrom, and c. means for axially moving the closure body to press said second sleeve into sealing engagement with the sealing ring to provide said seal between the frame and drum for eliminating said access.
 2. Separator accordIng to claim 1, and a condensate drain outfitted with a valve communicating with the casing for draining condensate from the casing with the closure body sealing the frame and drum.
 3. Separator according to claim 1, said means for axially moving the closure body comprising rotatable shafts each having integral with one end thereof an eccentrically mounted pin, recesses in said closure body receiving said pins.
 4. Separator according to claim 1, and a sealing gasket interposed between the sealing ring and said second sleeve mounted on the sealing ring or the second sleeve.
 5. Separator according to claim 4, the gasket being mounted on the second sleeve. 